Peristaltic pump

ABSTRACT

A pump comprising a housing; a motor mounted in the housing and configured to drive a rotor mounted on a shaft connected to the motor, and a first connector and a second connector each secured to the housing. The first and second connectors are in fluid communication by a tube arranged in the housing. The first connector is configured to connect to a first fluid line and the second connector is configured to connect to a second fluid line. In use, the rotor is configured to urge fluid within the tube from the first connector to the second connector when driven by the motor. The first and second connectors are releasably secured to the housing.

This invention relates to peristaltic pumps and rotors and connectors for use with a peristaltic pump.

BACKGROUND

Peristaltic pumps typically contain a head tube in fluid communication with a liquid source and a discharge line. A rotor is normally provided to squeeze a portion of the tube to drive liquid from the liquid source to the discharge line via the head tube. Over time, the head tube will eventually need to be replaced as it may have become damaged or stiffened with use. One problem with existing peristaltic pumps is the difficulty in removing and replacing a head tube, as this often requires disconnecting the pump from the discharge line in order to make the pump more accessible to a user. The user can then pull the head tube away from the rotor and separate the head tube from connectors connecting the head tube to the fluid lines. While pulling the head tube may not be a problem if the tube is damaged anyway, there may still be damage to the connectors. Furthermore, the need to disconnect the pump in order to provide better access for a user is undesirable, particularly as such pumps may be located in difficult to access locations such as in a roof space.

Furthermore, installing a new head tube typically requires the new tube be inserted in a narrow gap around the rotor and re-connected to the connectors of the pump. However, given the space constraints within the pump, this process is not simple and can take some time to ensure a fluid-tight connection is made between the replacement head tube and the pump connectors before re-installing the pump.

The ease of installation of existing pumps is further limited by the constraints imposed by the stiffness and location of the fluid lines and power cables to power the pump. As such, the pump often needs to be oriented and located in a particular way in order to accommodate the numerous constraints imposed by the fluid lines and the power cables. For example, it is not always possible to have the pump spaced from external surfaces, as ducting or mounting locations may require the pump to be secured against external surfaces. As such, it is sometimes necessary to bend or contort power or sensor cables connected to the pump so that constraints imposed by the fluid lines and external surfaces can be met. This can damage the sensor and/or power cables, causing the pump to become inoperable as well as requiring the damaged cables to be replaced.

The present invention seeks to ameliorate at least some of these issues.

BRIEF SUMMARY OF THE DISCLOSURE

Viewed from a first aspect, the present invention provides a pump comprising a housing; a motor mounted in the housing and configured to drive a rotor mounted on a shaft connected to the motor, and a first connector and a second connector each secured to the housing. The first and second connectors are in fluid communication by a tube arranged in the housing. The first connector is configured to connect to a first fluid line and the second connector is configured to connect to a second fluid line. In use, the rotor is configured to urge fluid within the tube from the first connector to the second connector when driven by the motor. The first and second connectors are releasably secured to the housing.

This arrangement means that the respective connections between the connectors and the first and second fluid lines can be maintained, so that only the connections between the connectors and the tube fluidly connecting the first and second connectors (known as a head tube) need to be disconnected and then re-established when replacing a head tube. Thus, maintaining the present pump is considerably more efficient than prior art pumps, as a user may use a single hand and no further tools to remove and replace the head tube.

Optionally, the first connector may comprise a first tab portion and the second connector may comprise a second tab portion, and the housing may comprise at least one slot configured to receive the first and second tab portions. Providing tabs on the connectors and a corresponding slot or slots within the housing provides a simple way of releasably securing the connectors to the housing by way of a friction fit, and a user may simply grip the tab, for example using a thumb and finger of a hand, and pull the tab to release the connector from the housing.

The housing may comprise a chamber, the rotor may be disposed in the chamber, the tube may pass through the chamber, and the slot may be formed in a side wall of the chamber.

The first connector and the second connector may each comprise a first part and a second part. The first part may extend along a first axis, and the second part may extend along a second axis. The second axis may form an angle with the first axis, and the second part may be configured to rotate relative to the first part about the first axis. The rotation of the first part relative to the second part allows fluid lines to be connected to the pump from a number of orientations, thus providing greater flexibility in the installation and servicing of the pump.

The first part may be releasably connected to the second part. The first part and second part may be releasably connected by a threaded connection. The releasable first and second parts advantageously provide a quick release mechanism that allows the second part to remain connected to the fluid line, while the first part of the connector remains attached to the pump housing. This provides a more convenient way of disconnecting the head tube from the fluid lines, compared to removing the entire connector from the housing with the head tube and fluid lines still connected to one another. The second part may also provide an integrated seal with the fluid line.

The rotor may comprise a plate mounted perpendicular to the shaft and at least one finger extending therefrom. The first connector may be disposed on a first side of the plate and the second connector may be disposed on a second side of the plate. The first and second sides may be opposed sides of the plate, and the at least one finger may be configured to guide the tube from the second side of the plate to the first side of the plate upon rotation of the rotor.

Viewed from a further independent aspect, there is also provided a pump comprising a housing; a motor mounted in the housing and configured to drive a rotor mounted on a shaft connected to the motor, and a first connector and a second connector each secured to the housing. The first and second connectors are in fluid communication by a tube arranged in the housing. The first connector is configured to connect to a first fluid line and the second connector is configured to connect to a second fluid line. In use, the rotor is configured to urge fluid within the tube from the first connector to the second connector when driven by the motor. The rotor comprises a plate and at least one finger extending therefrom. The first connector is disposed on a first side of the plate and the second connector is disposed on a second side of the plate. The first and second sides are opposed sides of the plate, and the at least one finger is configured to guide the tube from the second side of the plate to the first side of the plate upon rotation of the rotor.

Thus the present pump also facilitates the installation and removal of the head tube in a manner which does not require the housing to have a part that is removable to provide access to the head tube. The present pump advantageously does not require the rotor to be removed from the housing in order to replace the head tube, further facilitating the ease with which an installer can maintain the pump.

The first side of the plate may face the housing. The plate may define a plane and the finger may extend in a direction parallel to the plane. The finger may extend in the direction of rotation of the rotor. The finger may have an arcuate profile.

The rotor may comprise a rounded outer edge. The rotor may comprise a plurality of rollers distributed around a perimeter of the rotor. In use, the rotor may be configured to squeeze the tube against an inner surface of the housing.

The pump may further comprise a cover releasably attached to the housing. The cover may be configured to contain the rotor and tube within the housing. The cover may be tethered to the housing.

The motor may be a stepper motor. Use of a stepper motor is preferable as sufficiently high torques can be achieved without the use of a gear box, thus reducing the volume encompassed by the pump, a desirable attribute as such pumps are often installed in confined spaces. A stepper motor generates less heat, requires less power to run, and runs more reliably than conventional motors. A stepper motor may also be controlled by firmware, and thus more modes of operation of the pump can be achieved.

The pump may further comprise the second fluid line and a valve disposed in the second fluid line. The valve may be configured to substantially prevent ingress of fluid into the second connector from the second fluid line. Thus, when the second connector is disconnected from the head tube, this stops fluid from draining back out of the second connector, potentially causing liquid to drain onto the surrounding ducting or area, when replacing the head tube.

The housing may comprise a connection port spaced from an edge of the housing, and wherein the pump further comprises a flying lead connected to the connection port at a first end and having a connector at a second end, wherein the flying lead has a length greater than the spacing from the connection port to the edge of the housing. The pump may further comprise a power cable to power the pump. The motor shaft may extend along a shaft axis, and the power cable may extend from the housing in a direction substantially perpendicular to the shaft axis.

The pump may further comprise a controller configured to receive a signal from a liquid level sensor.

The first and second connectors may be releasably secured to the tube.

Viewed from a further independent aspect, there is also provided a rotor for use in a pump according to any of the appended claims, and a connector for use as the first or second connector in a pump according to any of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

FIGS. 1 & 2 illustrate perspective views of a peristatic pump;

FIG. 3 illustrates a perspective view of the pump of FIGS. 1 & 2 with the cover and rotor omitted and the connectors and interconnecting head tube separated from the pump housing;

FIG. 4 illustrates a side exploded view of the connectors and head tube;

FIG. 5 illustrates a front view of the peristaltic pump with the cover omitted;

FIG. 6 illustrates a rotor for the peristaltic pump of FIGS. 1 & 2 ;

FIG. 7A illustrates a side view of a power connector with a power cable extending from the pump body in a first configuration;

FIG. 7B illustrates a side view of a power connector with a power cable extending from the pump body in a second configuration.

DETAILED DESCRIPTION

FIGS. 1 & 2 illustrate perspective views of a peristatic pump 10. As illustrated, the pump is provided with a housing 15 having anti-vibration components 20 secured to upper and lower surfaces of the housing 15 and a cover 30 attached to a front portion 17 of the housing 15. Depressing a latch 35 on the cover 30 releases the cover 30 for removal from the housing 15 and enables a user to access a rotor 155 within the housing 15. An LED 25 is provided in the housing 15 to indicate an operating status of the peristaltic pump 10. Preferably the LED 25 protrudes from the front portion 17 of the housing 15 so that it is visible to users from a wider range of angles compared to if the LED 25 was within a recess in the housing 15. The cover is preferably made from a transparent material so a user is able to see the operation of the pump 10 without having to remove the cover 30. As shown in FIG. 2 , a flexible nylon tether 40 is shown securing the cover 30 to the housing 15. This is preferable to having a fully separable cover 30, as the user is able to remove the cover 30 from the housing 15 and does not need to hold onto the cover 30 during maintenance of the pump 10, or risk mis-placing the cover 30. It would be apparent that nylon is merely one example of a material suitable for use as the flexible tether 40. The housing 15 is also provided with a data port 45 for connection with a sensor (not shown). In some embodiments, the sensor provides data that controls the mode of operation of the pump. The sensor may not be hard wired to the pump 10 to provide greater flexibility during installation of the pump 10. For example, the pump 10 may be provided with a data cable (not shown) having a connector which can be connected to a corresponding connector and data cable of the sensor. Thus, an indirect connection can be provided between the pump 10 and the sensor. In some cases the sensor is a liquid level sensor, such as a hall effect float sensor or a capacitance sensor. Such a sensor provides the pump with data indicative of a liquid level within a reservoir (not shown) that the pump 10 is pumping fluid from. In some cases the sensor is a temperature sensor. The temperature sensor may measure differential air temperature or a temperature within the reservoir, such as a water temperature. A button 50 provides a user input that can be used to operate the pump, for example, to manually operate the pump to check the pump is operating normally, for example after a head tube 85 has been replaced (see FIGS. 3 & 4 ). A power port 55 is also provided in the housing 15 for connection to a power supply (not shown) to operate a pump motor (not shown) within the housing 15. Connectors 100A, 100B are also provided for releasably securing a head tube 85 to the housing 15. However, it would be apparent that it is not essential for the connectors 100A, 100B to be releasably secured to the housing 15. As shown, connector 100A connects a fluid inlet line (not shown), for example from a condensate reservoir, to the pump 10 and connector 100B connects a fluid outlet line (not shown) to the pump to discharge liquid from the reservoir.

The housing 15 preferably comprises one or more plastic materials. Fire retardant Acrylonitrile Butadiene Styrene (ABS) and fire retardant glass filled nylon are particularly preferable plastic materials as these provide a tough and durable body that meets regulatory fire standards. Fire retardant glass filled nylon also provides structural rigidity to the housing 15. Thus, a balance of fire retardance and rigidity can be achieved by making the rear of the housing 15 from fire retardant ABS and the front of the housing 15 from fire retardant glass filled nylon. However, it would be apparent other plastic materials would be suitable for use. The anti-vibration components 20 are made from thermoplastic elastomeric material and are preferably over-moulded to the housing 15. However, it would be apparent other materials would be suitable for dampening vibrations within the pump housing 15. The housing 15 is preferably sealed to prevent egress of liquid into the housing 15.

FIG. 3 illustrates a perspective view of the pump 10 with the cover 30 and rotor 155 omitted and the connectors 100A, 100B separated from the housing 15. As shown in FIG. 3 , the front portion 17 provides a chamber 70 and an inner surface 75 against which the head tube 85 is compressed, in use, by the rotor (see also FIG. 5 ). Preferably, one or more ribs 19 are provided on the housing to stiffen the front portion 17, so as to resist deflection of the front portion 17 during operation of the pump 10. The ribs 19 preferably extend in a direction substantially parallel to the shaft axis. The front portion 17 also includes two slots 80A, 80B for securing the releasable connectors 100A, 100B to the housing 15 by way of a friction fit. The slots 80A, 80B are sized so as to receive and grip a first part 105 of each of the releasable connectors 100A, 100B so that the user can manually release each connector 100 by pulling a tab portion 115 of the first part 105 away from the slot 80. Preferably the user is able to pull the first part 105 out of the slot 80 using a single hand. As shown in FIG. 3 , releasing both connectors 100A, 100B also releases the head tube 85 from the housing 15. This provides a particularly convenient way to remove and replace the head tube 85, for example once the head tube 85 has stiffened over time or has become damaged in use. A second part 110 of the connector 100 is also provided for connecting the respective fluid line to the first part 105 and thus the head tube 85, typically by way of a barbed end 150. Thus, a fluid flow path is provided from the fluid inlet line to the fluid outlet line via the respective connectors 100A, 100B and the interconnecting head tube 85. The first 105 and second 110 parts are preferably rotatably connected to one another such that, when the connector 100 is connected to the housing 15, the second part 110 can rotate from a first position where the second end 150 of the second part 110 is pointing perpendicular to the shaft 60, to a second position where the second end 150 points in a direction parallel to the shaft 60 (not shown). This is particularly advantageous, as leaving the fluid lines connected to the respective connectors 100A, 100B during replacement of the head tube 85 makes for a more efficient maintenance procedure, as the user simply removes the connectors 100A, 100B from the housing, removes the respective ends of the head tube 85 from the associated connectors 100A, 100B, connects the respective ends of a replacement head tube 85 to each associated connector 100A, 100B and fits the connectors 100A, 100B back to the housing 15. There is no need to also remove the drainage lines, which can be impractical due to the constraints imposed by their stiffness, orientation or location within the confined space in which peristaltic pumps are typically located.

FIG. 4 illustrates a side exploded view of the connectors 100 and head tube 85. In combination, these may be considered a head tube assembly. As illustrated, the head tube 85 has a first end 90 and a second end 95 and the first part 105 has a first end 120 and a second end 125. The first end 120 of the connector is preferably a barbed end to provide a more robust connection when inserted into a respective end 90, 95 of the head tube 85. The second part 110 has a first end 140 and a second end 150. The second end 125 of the first part 105 is configured to receive the first end 140 of the second part 110. A nut 145 attached to the second part 110 engages with a threaded portion 135 on the second end 125 of the first part 105 and provides a fluid-tight and secure connection between the first 105 and second 110 parts. While a threaded connection is shown, it would be apparent this was merely exemplary and that other releasable connections would be compatible with the present disclosure. By releasing the nut 145 on each connector, it is possible to separate the first and second parts, for example to facilitate easier release or attachment of the connector 100 to the housing 15, as explained below. A second end 150 of the second part 110 is preferably a barbed end and provides a robust connection to the respective fluid line. The connection between the second part 110 and the fluid line may be enhanced further by use of external clamps, for example using a cable or tie, to secure the fluid line to the second part 110.

FIG. 5 illustrates a side view of the peristaltic pump 10 with the cover 30 omitted. The connectors 100A, 100B are secured to the housing 15 and the head tube 85 is located within the chamber 70. A shaft 60 extends from the pump motor (not shown) housed within the housing 15 and a keyed portion 65 on the shaft 60 (see FIG. 3 ) engages with a corresponding keyed portion 157 on the rotor 155 (see FIG. 6 ) to drive the rotor 155. In use, the motor drives the rotor 155 about an axis of rotation and rollers 185 secured to the rotor 155 compress the head tube 85 in turn against the inner surface 75 of the front portion 17 to drive fluid from the first connector 100A to the second connector 100B.

As shown in FIG. 6 , the rotor 155 includes three rollers 185 secured between respective inner surfaces of an inner plate 160A and an outer plate 160B. The three rollers 185 are distributed evenly around the perimeter of the plates 160A, 160B which are fixedly aligned by the motor shaft 60 extending through an opening in each of the plates 160A, 160B. By using three rollers, more even pressure is applied to the head tube 85 and motor bearing (not shown) which increases the reliability of the pump and also reduces the amount of noise generated during operation of the pump 10. The outer plate 160B is also shown having three fingers 165 extending in a generally tangential direction in a plane defined by the outer plate 160B. The outer plate 160B preferably has a rounded edge profile 170 to reduce the risk of damaging the head tube 85 when removing or reinstalling a head tube 85. A notch or groove 175 is formed between each finger 165 and the outer plate 160B. While the rotor 155 illustrated in FIG. 5 rotates in a clockwise direction, it would be apparent that the rotor 155 could be driven in an anticlockwise direction also. Preferably the rotor is made from a metal material, such as die cast zinc to minimise distortion and wear of the rotor 155.

Each finger 165 of the outer plate 160B is configured to urge the head tube 85 from one side of the outer plate 160B to the other side of the plate. An exemplary method of removing the head tube 85 includes removing the cover 30, moving the rotor 155 to the position shown in FIG. 5 , releasing the first connector 100A from the housing 15 such that a portion of the head tube 85 extends outwardly of the housing, across the outer plate 160B as enabled by the space provided by the associated groove 175, rotating the rotor 155, for example by a user manually pushing the rotor 155 to draw the head tube 85 out of the chamber 70 as the rounded edge 170 of the outer plate 160B slides across an inboard surface of the head tube 85, removing the second connector 100B to release the head tube from the housing, and then disconnecting the head tube from the first and second connectors 100A, 100B.

As the rotor 155 is rotated to draw the head tube 85 out of the chamber 70, the proportion of the head tube 85 that is drawn out of the chamber 70 increases until the user can simply release the second connector 100B to remove the head tube 85 from the housing 15. As the head tube 85 is drawn out of the chamber 70, the first connector 100A and the portion of head tube 85 attached thereto extend away from an outer surface 180 of the outer plate 160B while the remainder of the head tube 85 and the second connector 100B remain in the chamber 70.

The existing head tube can then be replaced and a new head tube can be reattached to the respective first parts 105 of the connectors 100. The head tube assembly including the new head tube can then be re-installed in the chamber 70, for example, by first arranging the rotor 155 to the position shown in FIG. 5 and connecting the first connector 100A to the housing 15, as facilitated by the space provided by the associated groove 175. This leaves a small portion of the head tube 85 within the chamber 70 and the remainder of the head tube 85 and the second connector 100B outside the chamber 70, extending away from the outer surface 180 of the outer plate 160B. As the rotor 155 is rotated, for example manually by a user, the finger 165 will draw the head tube 85 into the chamber 70 as the rounded edge 170 of the outer plate 160B slides over the outboard surface of the head tube 85. Once most of the head tube 85 is located in the chamber 70, the second connector 100B can be connected to the housing 15 and the cover 30 re-attached to complete the replacement procedure. Thus, the fingers 165 of the rotor 155 are able to facilitate removal or insertion of a head tube 85 within the chamber 70. Instead of manually rotating the rotor 155, the user may operate the pump motor, for example by pressing the button 50, to drive the rotor 155 and draw the remainder of the head tube into position within the chamber 70. Once the replacement head tube is inside the chamber 70 the user can secure the second connector 100B to the housing 15 in the manner described above.

Whereas the tri-lobed profile of the outer plate 160B has been described in terms of fingers 165 projecting from a central portion, it will be appreciated that the same shape could alternatively be considered as a series of three cut-outs from a larger plate (such as a plate initially mirroring the circumferential profile of the inner plate).

Peristaltic pumps are typically connected to an external power source, such as a mains power supply by a power cable, or to a sensor by a data cable. FIGS. 7A and 7B illustrate examples of how a flying lead 190 may be arranged in relation to the housing 15 to facilitate installation of the pump 10 in confined spaces. In FIG. 7A, the flying lead 190 extends in a substantially perpendicular direction to a rear surface 195 of the pump housing 15, for example from power port 55 and terminating at a connector 197 for connection to a further power cable connected to the external power source. Such an arrangement is particularly useful when the pump does not need to be mounted in such a way that the rear surface 195 is secured against an external surface, such as a wall of a room (not shown). Whilst the pump 10 illustrated in FIG. 7A shows a flying lead 190 extending from the power port 55, a similar flying lead (not shown) may be used to facilitate access to other connection ports, such as data port 45 for connection to a liquid sensor (not shown), located in the rear surface 195. Providing one or more flying leads that extend in a direction substantially parallel to the rear surface allows for greater flexibility when installing the pump 10, as the pump 10 can be installed with the rear surface closer to the external surface, but a user does not need to access the rear surface 195 to establish electrical connections with the connection ports 45, 55 at the rear surface 195. For ease of installation, the present pump 10 can additionally or alternatively include a flying lead 190 that allows the sensor and power cable to be connected to the housing 15 using a single connector 197 having the necessary electrical connections for both the external power supply and the sensor. In this case, the minimum spacing between the pump 10 and the external surface would be the bend radius of the flying lead 190. In some cases, it may be desirable to have a single flying lead 190 connect to two or more connection ports 45, 55. In some cases the connector 197 can receive one or more cables for connection to respective sensors (not shown) in addition to the flying lead 190 that extends between the connector 197 and the pump 10. It should be noted, that even when a sensor is not present, providing a flying lead 190 for the power connection is still advantageous, as the user can place the pump 10 into position, leaving only the minimum spacing described above, but retain easy access to the connector 197. For example, if the flying lead 190 extends to the front surface of the housing 15, the user only needs to access the front of the pump 10 in order to establish a powered and/or data connection with the rear surface 195. It would be apparent the flying lead 190 may have a length greater than the width of the housing 15 such that the connector 197 is disposed on the side of the housing 15 for the user to access. The flying lead 190 can thus extend perpendicularly from the rear surface 195 or substantially parallel to the rear surface 195 or angles in between. It would also be apparent that while the flying lead 190 has been described as providing a single connector for two connectors disposed on a surface of the housing 15, more than two connectors could be connected to the flying lead 190 in order to facilitate installation of the pump 10.

Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. 

1. A pump comprising: a housing; a motor mounted in the housing and adapted to drive a rotor mounted on a shaft connected to the motor, and a first connector and a second connector each secured to the housing, wherein the first and second connectors are in fluid communication by a tube arranged in the housing, wherein the first connector is adapted to connect to a first fluid line and the second connector is adapted to connect to a second fluid line, wherein the rotor is adapted to urge fluid within the tube from the first connector to the second connector when driven by the motor, and wherein the first and second connectors are releasably secured to the housing.
 2. A pump as claimed in claim 1, wherein the first connector includes a first tab portion and the second connector comprises a second tab portion, and wherein the housing includes at least one slot configured to receive the first and second tab portions.
 3. A pump as claimed in claim 1, wherein the housing includes a chamber and the rotor is disposed in the chamber, wherein the tube passes through the chamber, and wherein the slot is formed in a side wall of the chamber.
 4. A pump as claimed in claim 1, wherein the first and second connectors each includes a first part and a second part, wherein the first part extends along a first axis, and the second part extends along a second axis, wherein the second axis forms an angle with the first axis, and wherein the second part is configured to rotate relative to the first part about the first axis.
 5. A pump as claimed in claim 4, wherein the first part is releasably connected to the second part.
 6. A pump as claimed in claim 5, wherein the first part and second part are releasably connected by a threaded connection.
 7. A pump as claimed in claim 1, wherein the rotor includes a plate mounted perpendicular to the shaft and at least one finger extending therefrom, wherein the first connector is disposed on a first side of the plate and the second connector is disposed on a second side of the plate, wherein the first and second sides are opposed sides of the plate, and wherein the at least one finger is adapted to guide the tube from the second side of the plate to the first side of the plate upon rotation of the rotor.
 8. A pump comprising: a housing; a motor mounted in the housing and adapted to drive a rotor mounted on a shaft connected to the motor, and a first connector and a second connector each secured to the housing, wherein the first and second connectors are in fluid communication by a tube arranged in the housing, wherein the first connector is adapted to connect to a first fluid line and the second connector is configured to connect to a second fluid line, wherein the rotor is adapted to urge fluid within the tube from the first connector to the second connector when driven by the motor, and wherein the rotor includes a plate and at least one finger extending therefrom, wherein the first connector is disposed on a first side of the plate and the second connector is disposed on a second side of the plate, wherein the first and second sides are opposed sides of the plate, and wherein the at least one finger is adapted to guide the tube from the second side of the plate to the first side of the plate upon rotation of the rotor.
 9. A pump as claimed in claim 7, wherein the first side of the plate faces the housing.
 10. A pump as claimed in claim 7, wherein the plate defines a plane and the finger extends in a direction parallel to the plane.
 11. A pump as claimed in claim 7, wherein the finger extends in the direction of rotation of the rotor.
 12. A pump as claimed in claim 7, wherein the finger has an arcuate profile.
 13. A pump as claimed in claim 1, wherein the rotor includes a rounded outer edge.
 14. A pump as claimed in claim 1, wherein the rotor includes a plurality of rollers distributed around a perimeter of the rotor, and wherein the rotor is adapted to squeeze the tube against an inner surface of the housing.
 15. A pump as claimed in claim 1 further comprising a cover releasably attached to the housing, wherein the cover is adapted to contain the rotor and tube within the housing.
 16. A pump as claimed in claim 15, wherein the cover is tethered to the housing.
 17. A pump as claimed in claim 1, wherein the motor is a stepper motor.
 18. A pump as claimed in claim 1 further comprising a second fluid line and a valve disposed in the second fluid line, wherein the valve is adapted to substantially prevent ingress of fluid into the second connector from the second fluid line.
 19. A pump as claimed in claim 1, wherein the housing includes a connection port spaced from an edge of the housing, and wherein the pump further includes a flying lead connected to the connection port at a first end and having a connector at a second end, wherein the flying lead has a length greater than the spacing from the connection port to the edge of the housing.
 20. A pump as claimed in claim 1, further comprising a controller adapted to receive a signal from a sensor.
 21. A pump as claimed in claim 1, wherein the first and second connectors are releasably secured to the tube. 22.-23. (canceled) 